1. Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA
2. Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA
3. U.S. Geological Survey, Flagstaff, Arizona 86001, USA
4. Division of Geosciences, School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona 86011, USA